1. Field of the Invention
The technical scope of the invention is that of deployable fins fitted onto projectiles.
2. Description of the Related Art
Projectile fins generally have a stabilizing role. They are grouped at a rear part of the projectile to form a tailpiece.
Certain projectiles have other fins whose role is that of guidance. These fins are generally placed at the front part of the projectile.
For reasons of their overall bulk and so as to enable firing from a gun barrel, the fins must be folded either backwards or forwards along the projectile, or inside it, before firing.
They must deploy upon exiting the gun barrel to ensure fulfill their stabilizing or guidance role.
Different solutions have been proposed to ensure this deployment function.
Patent FR2623898 thus describes a deployment device in which the fins are organized along an external wall of the projectile. Each fin is firstly driven by a back-geared motor which makes it pivot around an axis perpendicular to the plane of the fin.
Thereafter, it is made to pivot by the aerodynamic effect around an axis parallel to the plane of the fin.
This deployment mechanism is slow, which is why it is better suited to projectiles such as scatterable submunitions. Moreover, it requires the use of a back-geared motor for each fin. These motors are costly and occupy a considerable volume inside the projectile. The employment of such a mechanism is thus limited to intelligent sub-munitions in which the motors are moreover essential to ensure a guidance function after deployment.
Such a mechanism can not be envisaged for a projectile fired from a cannon and for which the deployment of the fins must be made immediately upon exiting the barrel in order to ensure the stabilization of the projectile and must use a minimum amount of space inside the projectile.